The present invention relates to an apparatus for controllably cooling metal items such as billets or the like and, in particular billets of aluminum alloys.
There are a number of processes which require that aluminum alloys be heat treated prior to extrusion. After heat treatment, e.g., homogenizing and/or heterogenizing, and prior to extrusion the alloys are cooled in a controlled manner. The object of the heat treatment and controlled cooling process is to modify the structure of the alloy in some desired manner in order to make subsequent extrusion easier. In addition, the process improves the mechanical properties of the extruded section as well as its surface quality.
The object of the present invention is to provide an improved apparatus which achieves a controlled cooling of each single item of material taking into account the dimensions of the item and its composition. The apparatus is capable of controlling the cooling rate and cooling time of the item, thus allowing constant quality to be achieved in each piece of material treated.